by answering to the question that why going to paradise does not cost a lot, professor Ansarian said: the only thing people need to do is saying “NO” to many sins, saying “NO” to numerous sins has no cost for you, for instance, if you say: I don’t want to drink wine, I don’t want to commit adultery, I don’t want to usurp people’s properties, I don’t want to cheat in business, I don’t want to be cruel toward my family, I don’t want to oppress the people of my country, I don’t want to reject people, saying these “NOs” has no cost. If you say your seventeen obligatory units of daily prayers, and fast during Ramadan month, and pay your Zakat and Khums, they have no cost either.
He also added: going to Paradise is like walking on a slippery slope and it is very easy, one can go to paradise by saying about a hundred “NOs”, and some physical efforts and some monetary expenses, but you have to spend a lot if you want to go to Hell. Those people who travel to some European countries during some special occasions like Nouroz Eid or other holidays and stay there for a couple of days and do many sins and corruptions, they need to spend a lot of money so that they can pave the way for getting their pass to Hell. If one doesn’t spend a lot, he is not let into the hell. One should spend like Mu'awiyah, Yazid, Ibn-Moljam, Shemr, and do a lot of sins and corruptions and commit adultery like them so that they can go to hell, but heaven does not have these costs; sometimes people make their ways to paradise without any cost, without a single Unit of prayer, without a day of fasting, without reciting Qur'an, and without paying zakat and Khums.
source : erfan.ir